Went to the boat today and the bowl was full again. But I had left the lever up (Duh!). Put it horizontal, pumped it dry and went sailing. After 2 hours or so of a very nice sail, and it was still, mostly empty. I went into the V berth and looked at the seacock under the hatch
and saw that there are 2 seacocks. One is the drain to the sink and the other is attached to the macerator. (is that legal
?) It was way too hot to spend too much time in there so I closed the macerator seacock. the other is open for the sink drain and I think it is also attached to the suction hose to draw water from the lake into the head to flush it.
Could this have been the problem all along?
I plan to go to the boat again some time this week in the morning when its cool enough to really check it out.